Pharmaceuticals for oral ingestion can take many different forms, such as liquids, emulsions, suspensions, aerosol sprays, solid capsules or tablets. Many pharmaceutical compositions including oral decongestants contain unpalatable ingredients and are therefore marketed in the form of liquids and sprays. Pharmaceutical compositions in the form of tablets or capsules which are intended to be swallowed whole are also widely marketed. Taste-masking of the active ingredients contained in such products can be effected by covering the tablet with a thin and quickly dissolving coating, for example, using a gelatin outer shell in order to retain the active ingredient until the tablet has been swallowed. Alternatively, the tablet can be compressed sufficiently so that it stays intact for the short time that it is in the mouth.
It would be desirable to provide solid, chewable and lozenge forms of dosage. These are preferred by people who do not like or have difficulty swallowing tablets or capsules, particularly children and older people. Furthermore, solid, chewable tablets have higher patient compliance than liquids since they are more convenient to carry around. Frequently the bitter taste of pharmaceutically-active ingredients has been masked so that such drugs can be adapted into acceptable-tasting chewable and lozenge forms.
The concept of providing pharmaceuticals in solid, chewable form has been disclosed in EP-A-0,459,695, where the chewable tablets are made from coated granules of medicament. The coating on these granules comprises a blend of cellulose acetate and/or cellulose acetate butyrate and hydroxypropyl cellulose and provides taste-masking of the active ingredient and sustained-release of the medicament.
EP-A-0,284,408 also discloses a chewable tablet comprising a controlled-release drug in which granules are coated with a polymer or copolymer of alkyl esters of acrylic and methacrylic acids and ethyl cellulose.
GB-A-2,166,651 relates to a controlled-release powder consisting of discrete microparticles for use in edible pharmaceutical compositions. The particles contain an active ingredient and optionally an excipient in intimate admixture with at least one non-toxic polymer. Each of the particles are in the form of a micromatrix with active ingredient and the excipient, if present, uniformly distributed throughout the matrix. These particles have an average size of between 0.1 and 125 .mu.m.
EP-A-0,212,641 discloses a porous drug-polymer matrix with an amino- or amido- containing drug such as dimenhydrinate or salt thereof as the active ingredient and a pharmaceutically-acceptable copolymer having a plurality of carboxylic acid and ester groups wherein the matrix dissociates in a media having a pH of less than 4, thereby releasing the active ingredient into the acidic media of the stomach.
U.S. Pat. No. 3,629,392 discloses an aqueous latex of a polymer having acidic and/or basic groups in contact with a drug also having basic and/or acidic groups. The water is then removed and the product formulated into a suitable dosage form. An aqueous "latex" herein means an aqueous dispersion of colloidal or near colloidal particles.
U.S. Pat. No. 3,515,781 discloses a capsule containing menthol, thymol and an oral decongestant and which dissolves in the mouth to release these substances for the alleviation of the symptoms of nasal congestion.
While there has been a number of proposals in the art for providing oral decongestants and other orally-ingestible pharmaceuticals in chewable, sustained- or controlled-release tablet form, there has apparently been no disclosure of an oral decongestant composition in solid, chewable dosage form which allows for fast release of the decongestant, together with improved taste and consumer acceptability.
Accordingly, the present invention provides a chewable oral decongestant composition having enhanced release characteristics combined with improved taste and consumer acceptability.